Jacquard for weaving looms



Feb. 8, 1955 o. DALLE JACQUARD FOR WEAVING LOYOMS 2 Shets-Sheet 1 Filed Jan. 26, 1954 Feb. 8, 1955 o. DALLE JACQUARD FOR WEAVING LOOMS Filed Jan. 26, 1954 2 Sheets-Sheet 2 INVE 'TOR. 49% HA.)

Arm Y5 United States Patent JACQUARD FOR WEAVING LOOMS Olivier Dalle, St.-Cyr-au-Mont-d0r, France, assignor to Societe des Mecaniques Verdol, Lyon, France, a French limited liability company Application January 26, 1954, Serial No. 406,254

Claims priority, application France January 30, 1953 3 Claims. (Cl. 139-59) This invention refers to Jacquards for weaving looms and more particularly to Verdol Jacquards for high speed looms.

It is known that when the operating speed of a Jacquard is increased above a given limit faults are liable to occur under the action of a number of phenomena such as vibrations, inertia effects, etc. This limit may be raised with the so-called double-lift or two-shed Verdol Jacquard wherein each warp thread is controlled by two elementary hooks cooperating with two grid frames moving in opposed direction. However this increased operating speed is insuflicient with modern high speed looms, even when the Jacquard is provided with a fixed grid or open-shed grid adapted to retain the hooks at the raised position whenever they are to remain high during a number of successive strokes of the loom.

It has been observed that when a two-shed Verdol Jacquard is operated at very high speed, the faults are mainly caused by a defective downward movement of the hooks. The hooks are only returned downwardly by the leads attached to the cords. The weight of the leads has therefore to overcome the frictional forces and at high speed the inertia of the leads themselves has a noticeable effect, in such a manner that a frictional force which would not interefere with the proper operation of the Jacquard at normal speed may on the contrary unduly retard the return movement of the hook under consideration at high speed.

The present invention has for its object to provide means whereby these drawbacks may be overcome in J acquards of the two-shed type and more particularly in such Jacquards comprising an open-shed grid.

According to this invention means are provided whereby each hook which has to sink from the raised towards the lowered position is positively driven by the grid which is then moving downwardly.

In a first embodiment of the invention each grid frame comprises transverse bars so arranged as to strike down- Wardly the hooks which have to be lowered while being without action on those which have to be again raised by the other grid frame or, in an open-shed Jacquard, which are to remain at the raised position.

In a Verdol Jacquard of the two-shed type the hooks are normally engaged by the knives of the grid frames and only those which have been pushed by the corresponding needles may escape this engagement. The hooks which had previously been raised and which have to return towards the lowered position are therefore deviated by their needles and it will be appreciated that the aforesaid transverse bars may be so arranged on the sinking grid frame as only to strike these hooks, whereby the latter will be positively returned in spite of the frictional forces, inertia effects, etc. As to the hooks which have not been deviated by the corresponding needles, in an open-shed Verdol Jacquard they are retained at the raised position and in a Verdol Jacquard without open-shed device, they are to be re-engaged by the ascending grid frame and even if they were fully retained at the raised position by the frictional forces, this would be without inconvenience. It should besides be remarked that these hooks are not pressed transversely by their needles, whereby the main cause of frictional forces is avoided.

in another embodiment of this invention the end of the wire forming each elementary hook is turned horizontally and inwardly with respect to the hook, and each grid knife is provided with a longitudinal depression adapted to hook 1.

receive the turned end of the corresponding elementary hooks When the latter are deviated by their needles, whereby the hook is positively lowered by the knife during the downward movement of the latter.

In the annexed drawing:

Fig. 1 is a side view showing a double hook of a twoshed Verdol Jacquard, at the low position.

Fig. 2 shows this hook when it has been raised by one of the grid frames of the Jacquard.

Fig. 3 also shows this same hook at the raised position, but assuming it has been raised by the other grid frame of the Jacquard.

Fig. 4 is a fragmental view showing three successive hooks in a two-shed Verdol Jacquard according to the invention.

Fig. 5 illustrates the two first hooks of Fig 4 after they have been raised by one of the grid frames.

Figs. 6 to 8 show these hooks at three successive positions during the sinking step.

Fig. 9 is a view similar to Fig. 6, but in which it has been assumed that the first hook fails to sink at the same speed as the corresponding frame.

Figs. 10 and 11 are views similar to Figs. 4 and 5, but assuming the hooks are raised by the second grid frame of the Jacquard.

Figs. 12 and 13 are enlarged fragmental views showing an elementary hook and the corresponding knife according to the second embodiment of this invention, gi is ligok being undeviated in Fig. 12 and deviated in Fig. 14 is a view similar to Fig. 5, but corresponding to the second embodiment of the invention.

In Fig. l a double hook of a two-shed Verdol Jacquard comprises two elementary hooks 1 and 2 of unequal height formed by one and the same wire suitably bent in the form of a hair pin. The harness cord 3 is attached to the lower part of the double hook and it is loaded by a lead 4. The corresponding warp thread, not illustrated, is attached to the cord 3 in the conventional manner. The double hook described cooperates with two knifes 5 and 6 carried by two grid frames not shown which rise and sink alternately in opposed relation (that is with a phase difference of at a frequency which is one half the frequency of operation of the loom slay. At the position illustrated the elementary hook 2 is being engaged by knife 6 and it will be subsequently raised by the same to the position of Fig. 2.

A needle '7 is associated to the double hook 1, 2 such needle being movable longitudinally in a horizontal plane to push transversely the longer leg corresponding to the elementary hook 1. In Fig. l needle 7 is not actuated. The double hook 1, 2 is besides guided by a lower transverse bar 8.

When the double hook is at the raised position of Fig. 2, if the corresponding needle 7 is pushed towards the right the longer leg of the hook is deviated towards the right as indicated in broken lines. The shorter leg is retained at its upper end by engagement of the elementary hook 2 with the knife 6 but this leg is bent elastically as shown. When the knife 6 will sink with the corresponding grid frame, the double hook 1, 2 will sink therewith and since the elementary hook it has been deviated towards the right it will not be caught by the knife 5 of the other grid frame and the double hook will therefore return to the low position of Fig. 1. But during this downward movement the longer leg of the hook will have to slide through the eyelet of needle 7 whereby frictional forces will be developed. These forces tend to retard the downward movement of the hook against the action of the lead 4. At low operating speed they are negligible, but at very high speed they may cause faults in operation.

If in Fig. 1 it had been assumed that knife 6 was high and knife 5 low, the double hook I, 2 would also have been raised by engagement of knife 5 with the elementary If the corresponding needle had then been actuated, the resulting pressure would have bent the longer leg of the hook and the shorter leg would have been deviated towards the right as shown in Fig. 3, whereby it would have escaped the ascending knife 6 during the downward movement of knife 5. Here also the longer leg of the double hook would have to slide through the eyelet of the needle 7. It may even be remarked that in this case the frictional pressure would be higher than in the case of Fig. 2 since the longer leg of the double hook is retained at both ends instead of but at its lower end as in Fig. 2.

If it is now assumed that the double hook 12 is to be high again at the next stroke of the loorn, then needle 7 remains inactive. The double hook first sinks with the descending knife 6 (Fig. 2) or (Fig. 3), but its elementary hook I or 2 is caught by the ascending knife 5 or 6 and the double hook is thus again raised.

In an open-shed Jacquard a double hook which has been raised and which is to be high at the next stroke of the loom does not effect this partial downward stroke followed by an upward return movement and it is on the contrary retained at the high position. The longer leg is formed with a nose 9 in the form of a ratchet tooth which cooperates with a fixed bar 10. The hook may be raised freely, but it is retained by bar if it is not actuated by the corresponding needle. When the needle 7 is pushed the longer leg of the double hook is deviated and nose 9 escapes the retaining or open-shed bar 10. In such a Jacquard the hooks which have to be high during a number of strokes of the loom are not lowered and raised between two successive strokes, which reduce the phenomena of inertia. But this open-shed device fails to ensure a positive and safe lowering movement of the hooks which have to pass from the high to the low position and as aforesaid it has been remarked that the faults in operation at high speed are due to such hooks which do not reach the low position in due time.

In a first embodiment of this invention there is associated to each knife of the grids a transverse bar so arranged as to be disposed above the elementary hook corresponding to the preceding of following knife of the other grid frame, when this elementary hook has been deviated under the action of the needle corresponding to the double hook of which the elementary hook under consideration forms a part. In Fig. 4, which shows three successive double hooks la-Za, 1b--2b and 1c2c at the low position, to each knife 5a, 5b, 5c of one grid frame there is associated a transverse bar 10a, 10b, 10c and in the same manner to each knife 6a, 6b, 6c of the other grid frame there is associated a transverse bar 11a, 11b, 11c. Assuming now the double hooks have been raised by the grid knives 6a, 6b, 6c engaging the smaller elementary hooks 2a, 2b, 2c, as above explained with reference to Fig. 2, when the elementary hook 1a is deviated under the action of the needle (not shown) corresponding to the double hook 1a2a (position of Fig. 5) this elementary hook 1a is situated beneath the transverse bar 11a associated to the knife 6a, i. e. to the knife which follows the knife 5a corresponding to the elementary hook under consideration. In the same manner, if it is assumed that the double hooks under consideration have been raised by the grid knives 5a, 5b engaging the longer elementary hooks 1a, 1b, as above explained with reference to Fig. 3 when the elementary hook 2a is deviated, as illustrated in Fig. 11, it is situated beneath the transverse bar 10b associated to the knife 5b which follows the knife 6a corresponding to the elementary hook under consideration. Moreover the vertical distance r (Fig. 5) between the deviated elementary hook and the transverse bar is smaller than the depth s of the hooked portion of an elementary hook.

For a clear description of the operation, it will be assumed that in Fig. 5 the double hook 1a2a should be lowered while the double hook 1b2b should remain high. The needle corresponding to the former will therefore be pushed by the corresponding pusher rod and the longer leg of the double hook will be deviated towards the right as indicated, the shorter leg being retained by engagement of the corresponding elementary hook 2a with the grid knife 6a as above explained with reference to Fig. 2. The double hook 1a2a will therefore be free to move downwardly with the descending grid frame (knife 6a) and if this downward movement is effected normally the double hook will remain suspended to the knife 6a. Fig. 6 illustrates an intermediate position of the parts during this regular downward movement. In Fig. 6 it has been assumed that the Verdol Jacquard was not of the open-shed type and therefore the double hook 1b2b at first moves downwardly, but sinCe i s longer leg has not been deviated by the corresponding needle, its elementary hook 1b will be caught by the grid knife 5b and will be raised again. Figs. 7 and 8 clearly show the successive steps of operation.

But if for any reason the double hook 1a2a fails to move down regularly with the descending grid frame, for instance if it is retarded by frictional forces, the transverse bar 11a strikes the elementary hook 1a shown in Fig. 9 and drives positively the double hook downwardly without the other elementary hook 2a becoming disengaged from the corresponding grid knife 6a since, as above explained with reference to Fig. 5, the initial play r between the transverse bar 11a and the elementary hook 1a is smaller than the depth s of the elementary hooks.

It should be noted that the transverse bar 11a does not drive the elementary hook 111 during the full downward stroke of the descending grid frame. Slightly before the end of this stroke the needles are no more actuated by the pusher rods and therefore the elementary hook 1a returns to the left and escapes the bar 11a. But this only occurs when the lowermost position of the double hook is almost reached and the kinetic energy of the lead is then such that this position is always reached in spite of the eventual frictional forces. It should besides be observed that since the corresponding needle is no more actuated, the frictional forces developed within the guiding eyelet of the needle are then negligible.

It has been supposed in Fig. 4 that the grid frame 6a was at the low position, but it will easily be appreciated that the above explanations would remain the same, mutatis mutandis, if this frame had been at the high position, as shown in Fig. 10. In such a case the three double hooks illustrated are raised (assuming, as in Fig. 4, that they are not actuated by their needles) by the ascending grid knives 5a, 5b, 50, which engage the elementary hooks 1a, 1b, 1c. The parts thus reach the position of Fig. 11. In this figure it has been supposed, as in Fig. 5, that the first double hook 1a-2a was to be lowered for the next stroke of the loom. The corresponding needle is therefore actuated by the appropriate pusher rod and, as explained with reference to Fig. 3, this causes deviation of the smaller leg of the double hook towards the right. The elementary hook 2a will thus escape the ascending grid knife 6a and the double hook will be free to effect its full downward stroke with the descending grid knife 5a. But if for any reason it failed to move regularly with the said knife, it would be positively driven by the transverse bar 10b.

The transverse bars 10a, 10b, etc.; 11a, 11b, etc. there- {lorekalways ensure positive downward movement of the In Figs. 4 to 11 it has been supposed that the Verdol Jacquard was of the two-shed type without the openshed device (nose 9 and bar 10 of Figs. 1 to 3). But it will be readily understood that the positive drive of the descending hooks is also ensured in the same way in openshed Jacquards. For instance, considering Fig. 5, in the case of an open-shed Jacquard the sole difference would be that the double hook lb-Zb which is high and which is to be high also at the next stroke of the loom will be retained by the open-shed device.

In the embodiment of Figs. 12 and 13 each elementary hook 12 is curved at 270 instead of as in the con ventional construction in such a manner that its end 13 is turned horizontally and inwardly towards the grid knife 14 which is shown at the engaged position in both figures. The portion of the knife facing the end 13 is formed with a lateral groove 15 adapted to receive end 13 (position of Fig. 13).

When the double hooks are not actuated by the needles their legs slide on the knives and the ends 13 do not engage the grooves 15. But when a double hook is deviated by the corresponding needle the end 13 of one of its elementary hooks becomes engaged into the corresponding groove 15 and is thus positively driven by the knife 14 (Fig. 13) as well downwardly as upwardly.

In Fig. 14, as in Fig. 5, two successive double hooks Ila-16a, 12b16b have been raised by the knives 17a and 17b of a grid frame of the Jacquard. The first one should be high at the next stroke of the loom while the second one should be low. The first one 12a16a is therefore actuated by the corresponding needle as explained with reference to Fig. 2. The elementary hook 12a which is quite free, will be deviated, while the other elementary hook 16a will be retained by the corresponding grid knife 17a. But the end of the latter will engage the lateral groove of the knife and the double hook Ila-16a will therefore be positively driven downwardly by the grid frame 17a17b in spite of any frictional forces. As to the double hook 12b-16b, the end of the elementary hook 16b supported by the grid knife 17]; remains spaced from the lateral groove of the knife, whereby the double hook may be caught and raised by the ascending grid frame, or may be retained at the high position by an open-shed device.

In the preceding description it has been supposed that each double hook was formed of a longer elementary hook followed by a shorter elementary hook, the first one receiving the action of the needle. But it will be understood that the invention may also be applied in the case of Jacquards wherein the first elementary hook is the shorter one, or wherein both elementary hooks are of the same length. Also although the invention is more particularly intended for Verdol Jacquards because this type of Jacquard is the most appropriate for high-speed operation, it may as well be used in connection with ordinary Jacquards of the open-shed type wherein the arrangement of double hooks and grid frames is quite similar.

I claim:

1. In a two-shed Jacquard for weaving looms of the kind comprising two grid frames reciprocating vertically in opposed direction, transverse knives fixed to each grid frame, each knife of one grid frame being disposed between two successive knives of the other grid frame; double hooks adapted to cooperate respectively with one knife of one grid frame and with one knife of the other grid frame; needles acting on said double hooks to deviate same and to cause same not to be caught by the knives of the ascending grid frame in accordance with the design; and means carried by the grid frames to positively drive downwardly one of the elementary hooks of each of the double hooks which have to pass from the raised position to the lowered position.

2. In a two-shed Jacquard for weaving looms of the kind comprising two grid frames reciprocating vertically in opposed direction, transverse knives fixed to each grid frame, each knife of one grid being disposed between two successive knives of the other grid frame; double hooks adapted to cooperate respectively with one knife of one grid frame and with one knife of the other grid frame; needles acting on said double hooks to deviate same and to cause same not to be caught by the knives of the ascending grid frame in accordance with the design; and transverse bars on each grid frame so disposed that each transverse bar of one grid frame is situated immediately above those of the elementary hooks adapted to cooperate with one of the two next knives of the other grid frame, which correspond to double hooks having to pass from the raised to the lowered position.

3. In a two-shed Jacquard for weaving looms of the kind comprising two grid frames reciprocating vertically in opposed direction, transverse knives fixed to each grid frame, each one of said knives being formed with a lateral longitudinal groove and each knife of one grid frame being disposed between two successive knives of the other grid frame; double hooks each formed of two elementary hooks with inturned ends adapted to cooperate respectively with one knife of one grid frame and with one knife of the other grid frame; and needles acting on said double hooks to deviate same and to cause same not to be caught by the knives of the ascending grid frame in accordance with the design, the inturned end of one of the elementary hooks of each of the double hooks which have to pass from the raised to the lowered position and which have been deviated by said needles engaging the groove of the knife by which said lastnamed elementary hook is supported to be positively driven downwardly by said last-named knife.

No references cited. 

